Originally Posted by Adam Schneider
Is it just rainwater/runoff? I don't remember any bodies of water over there...
Yes just rainwater/snowmelt drainage.
However the park is on the South Santiam river and it crested on Friday the 2nd at a level that exceeded the 1997 flood (listed as record since both dams upstream went operational in 1966) and it must have been higher than the 1996 flood which surprises me. Anyway with the park gates remaining open the river must not have flooded any of the park.